Synchronizing system.



-A. F. D-iXON.

SYNCHRONIZING SYSTEM.

APPLICATION FILED APR. 11. 1914.

1,258,546. i Paixmted Mar. 5, 1918.

3 SHEETS-SHEET l.

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SYNCHRONIZING SYSTEM,

APPLICATION HLED APR. 11 I914.

Patented Mar. 5, 1918.

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A. F. DIXON.

SYNCHRONIZIING SYSTEM, APPLICATION FILED APR. 11. m4.

1,258,540. Patented Mar. 5,1918.

3 SHEETS-SHEET 3- Wiltmssw: jmmn 507? UNITED STATES PATENT OFFICE.

AMOS F. DIXON, 0F NEWARK, NEW JERSEY, ASSIGNOR, BY IVIESNE ASSIGNMENTS,TO WESTERN ELECTRIC COMPANY, INGQRPGBhTED, A CORPORATION OF NEW YORK.

SYNCHRONIZING Specification of Letters Patent.

Patented Mar. 5,1918.

Application filed April 11, 1914. Serial No. 831,157.

T 0 all whom it may concern:

Be it known that I, Amos F. DIXoN, a citizen of the United States,residing at Newark, in the county of Essex and State of New Jersey, haveinvented a certain new and useful Improvement in Synchronizing Systems,of which the following is a full, clear, concise, and exact description.

This invention relates to synchronizing systems and has for its object asystem for maintaining in synchronism motor driven rotating mechanismsat the distant ends of a signal transmitting circuit.

The invention as herein shown and as it is particularly designed to beutilized is embodied in a printing telegraph system of the usualmultiplex high speed type in which distributers are located at distantstations at the ends of a single signal transmitting circuit whichdistributers associate such circuit simultaneously with thecorresponding transmitting and receiving elements at the distantstations.

In order that a receiving mechanism at one station may be associatedwith the signal circuit at such station during the same period that thetransmitting mechanism individual thereto at the other of such stationsis connected to such circuit some means must be provided forsynchronizing the dis tributers. In systems of this character it isusual that the signals are made up of a plurality of current impulses ofopposite character or polarity, the system being such that one of suchsignals comprising a plurality of impulses may be transmitted from atransmitting mechanism to its receiving mechanism each time they areassociated with each other over the signal circuit by the distributers.

A particular feature of the present invention is the arrangement wherebythe local correcting current impulses are provided by the employment ofa greatly reduced number of circuit contacts. This result isaccomplished by the use of a transformer made momentarily active throughthe agency of the changes in polarity or potential of the line currentimpulses and associated with the speed controlling mechanism in such amanner as to control the movement of one of the distributors to keep itinsynchronism with another. By the use of a transformer, instead of theusual re lays pends he tannins ea ner impulses the number of movingcontacts and consequently the amount of adjustment is reduced and theliability of defective or varying cooperation iat a minimum. The above,and other objects of this invention will. be fully set forth in thefollowing description and claims, and will be more readily understood byreference to the accompanying drawings wherein Figure 1 showsdiagrammatically the sending and receiving distributors and ohcuitconnections therefor.

Fig. 2 is a diagrammatic view of the circuits and apparatus shown atthereceiving station in Fig. 1, showing the distribut'er contacts indeveloped plan.

Fig. 3 is a side 'elevaton of the correcting mechanism for adistributor, and

Fig. at is a section on the line IV IV of F ig. 3.

P te to Fig. 1, the line from the transmitting station A, to'thereceiving station B, is shown at 1, and the receiving line rela at 2.The line relay 2 is of the polar ized type and the armature thereof ismoved against upper contact 3 by a positive current impulse and againstthe lower contact a by a negative current impulse so that for each rangeof polarity of the line cur rent the armature 5 moves from one contactto the other and always remains in contact with one the other ofcontacts 3 and 4:. A source of energy shown as a battery 6 is connectedto the armature The upper contact 8 is connected to the four segments '7of the receiving distributer by the conductor 8. In addition to the segments 7 coma ts O are provided located be tween the segments '7 and incircumferential alinement therewith so that the brush 10 carried on therotating arm 11 will alternately rub over the segments 7 and thecontacts Arranged in the circumference of a larger concentric circle area plurality of contacts 12. In the receiving distributer siown therefive of these contacts for each segment 7, as the well known Baudotalphabet requires various combinations of 5 impulses made up of positiveand negative impulses. Obviously if it were desired to employ some otheralphabet the number of contacts 12 could be'alter'ed to meet therequirements of such alphabet In the sys; tem disclosed as there areonly four seg-. me s d mmed" there would be tw nty contacts 12. Howeveronly the contacts 12 corresponding to two segme -ts 7 are shown on thedrawing it being understood that there may be as many segments 7 and contacts 12 as may be desired. Between each set of contacts 12 anadditional contact 13 is located radially opposite the contact 9. Thebrush 1% which is electrically connected to the brush 10 is adapted tosweep over and make contact with the contacts 12 and 13, during themotion of the brush carrying arm 11. The arrangement is such that as thebrush carrying arm rotates the segments 7 and contacts 12 will beelectrically connected and the contacts 9 and 13 electrically connected.The construction of the receiving distributor described thus far doesnot differ materially from the Baudot distributer the construction andoperation of which is well known in the art.

In addition to the contacts described above, which are equivalent to thecontacts of the Baudot distributer a set of synchronizing contacts 15-,which correspond in number to the contacts 12, are provided, as well asthe continuous contact 16. As shown on the drawing the contacts 15 arearranged in a concentric circle of larger diameter than that of thecontacts 12. It will also be observed tha the synchronizing contacts 15are shorter than the contacts 12. The rela- 'tive positions of thecontacts 12 and 15 will be more fully described in connection with Fig.2, and the operation or" the system. The rotating brush carrying arm 11is provided with two electrically connected brushes 16 and 17 which areinsulated from the brushes 10 and 1 1, the arrangement of the brushes i6and 17 being such that at certain times during the travel of the brushcarrying member the contact 15 will be electrically connected to thecontact 16.

Connected with each of the contacts 12 of a set is one of a set of 5selecting magnets 18 which when energized in various combinationsdetermine the actuation of apparatus not shown to cause the recordationof the corresponding character. This apparatus may be of any o1 severalwell known types and as it forms no part or the present invention willnot be "further described.

Neglecting for the time the operation of synchronizing the operation ofselecting a desired character may be briefly described. Assuming thatthe distributor brush carrying arm 11 is driven in the direction of thearrow in synchronism with a corresponding distributor arm 42 located atthe sending station A, the brushes 10 and 11 will make contact with thesegments 1' and contacts 12 at the same instant as the correspondingbrushes of the distributor at the sending station make contact with thcorresponding contacts and se ments. For every positive impulse ofcurrent originating at the sending nesaseo station A the armature 5 ofthe polarized relay 2 makes contact with the contact It" at the time apositive impulse is sent the brush is in contact with a contact 12 thecorresponding selecting magnet 18 will be energized over a circuit whichmay be traced as follows: battery 6, armature 5, contact 3, conductor 8,egment 7, brushes 10 and 1 1, contact 1 selecting m gnct 18 to ground.If however at the 'ne the brush 1O maices contact with a contact anegative impulse arrives from the sending station the arn'1a ture 5 willbe shifted to the contact ii and the selecting magnet corresponding tosuch contact 12 will not be enern'ivod. Thus 'w l the distributor brushcai-l'aung arm 11 pr s over a given set of contacts 12 as many of theselecting magnets 18 will be energized there are positive impulses sentduring that time and such magnets will be energized or remaindeencrgized in a sequence corresponding to the combination of positiveand negative in'ipulses sent. immediately after the brushes leave thesegment 7 the brushes bridge the contacts 9 and 13 and close a circuitfor governing the recordation of a character. @bviously in order thatthe s'gelecting magnets may be properly energized it is necessa v thatthe distribute:- Uns of the di tributors at hot and receiving station bema ained in practi' lly exact synchroni in accordance with the presentin've..on this s ncrouism is obtained by means of circui and apparatuswhich wi i now be described.

.ch distributer is provided with a. motor which is adjusted to drive thedistributor arms approximately in synchronism. These motors may beclockwork, a phonic motor controlled from a vibrating reed or tuningfork, or any other suitable construction. The distributor arm is drivenfrom the mo tor through a correcting mechanism which will now bedescribed. It is only necessary however to provide such correctingmechanism for one distributor of a pair, which distributor may forconvenicce be referred to as the corrected or synchronized distributerthe other as the correcting distributor. The motors are adjusted so thatthe corrected distributer normally rotates either slightly faster orslower than the correcting or noncorrected distributor, the onlydilterence being that in the former case the correcting mechanism isemployed to retard or slow down the corrected distributor and in thelatter case to acvance or speed up the corrected distributer.

it. correcting mechanism for use in case the corrected distributer isset to run faster than the correcting distributer is shown in Figs. 3and A motor of any type is indicated at 20, which drives a shaft 21 uponwhich is fixed a gear wheel 22. Cooperating 22 and mounted in a frame 23with the gear is a pinion 24. The frame 23 is mounted to rotate about anaxis in alinement with the axis of the shaft 21 so that the pinion 2 land gear wheel 22 form an ordinary planetary gear. The electricalconnections between the stationary and movable parts are maintained inthe usual manner by means of a slip ring 40 and a current-carrying brush41. The frame 23 is mounted on a shaft 25 and is rotatable therewith.The brush carrying arm 11 is also fixed upon the shaft so that theangular relation of the frame 23 and arm 1.1 is constant. It is obviousthat if the pinion 24 were clamped so that it could not rotate theshafts 25 and 21 would rotate together at the same speed and if thepinion were rotated there would be a relative movement be tween saidshafts. Assuming the shaft 21 to rotate in the direction of the arrowshown thereon the speed of the shaft 25 would be decreased relative toshaft 21 by an amount depending upon the amount and speed of rotation ofthe pinion 24:. The pinion 2lis arranged to be rotated through theagency of a magnet 26 carried on the shaft 25, which magnet is energizedat the proper time as will be desc 'ibed later to slow down thedistributor brushes. The magnet 26 is provided with a pivoted armature27, which is in the form of a lever and carrie at one end a pawl 28,which coiiperates with a ratchet wheel 29 fixed to the shaft 30, whichalso carries the pinion 24. A spring 50 is provided to hold the pawl inengagement with the ratchet wheel and any suitable form of detent (notshown) may be provided to prevent over-running of the ratchet wheel. Thearrangement is such that upon the energization of the magnet 26, thearmature 27 moving toward the pole pieces 31 causes the pawl 28 toengage the ratchet wheel and rotate the pinion 2a in the direction ofthe arrow. Therefore it follows that for every ener ization of themagnet 26 th speed of the brush carrying arm is retarded, or in otherwords the brushes are mechanically set back. The armature 27 alsooperates a pair of normally closed contact springs 32 and 33, theoperation of which will be described later.

Referring now to Fig, 2 wherein the receiving distributor contacts areshown as developed, that part of the system which relates moreparticularly to the synchronizing operation may be described. The partsshown in Fig. 1 are designated by corresponding numerals on Fig. 2although but one segment 7 and one set of contacts 12 and 15 are shown.The contacts 15 are connected in multiple to a conductor leading to onewinding of a locking relay. The lower contact 4: of the polar relay 2 isconnected to earth through a winding of the transformer 35. The secondwinding of the transformer 35 is connected to the contact 16. As theline signals of five impulses are made up of combinations of positiveanl negative impulses it may be safely assumed that under ordinaryconditions the impulses will change, in polarity, on an average of atleast once for each character. For every change in polarity the armature5 will be shifted and a sychronizing impulse will be produced. Acharacteristic signal is graphically indicated above the receivingdistributor contacts in the relation they bear to such contacts. Thissignal consists of two positive impulses, followed by two negative and apositive impulse, so that there are two changes of polarity for thesignal. At the time the first change of polarity occurs provided thecorrected clistributer is in exact sychronism with the correctingdistributer the brush 1% will be just about to make contact with thethird segment 12 and the brush 1'? just about to contact with the thirdsegment 15. Although the armature 5 will shift and send an impulsethrough the transformer this impuse will be ineffective as there will beno connection between the contacts 15 and 16. If however the correcteddistributer is moving faster than the correcting distributer then brush17 will be in contact with the third contact 15 before the change inpolarity occurs. In this case the shifting of the armature 5 will sendan impulse from battery 6 through the primary of the transformer 35which will induce a corresponding impulse in the secondary which willpass through the contacts 16 and 15 now connected by the brushes L6 and17, through the relay 34. This causes the energization of relay 3% whichcauses the energization of magnet 26 and remains locked up over itsholding winding until the magnet 26 opens the contacts 32 and 33. As thecontacts and 33 are arranged so that they will be opened only at thefinish of the movement of the stroke of the armature of magnet 26, therelay n will hold up until after the completion of the operation ofmagnet Th energization of magnet 26 through the. agency of thecorrecting mechanism described above, will mechanically retard or setback the brushes of the corrected distributor. The opening of thecontacts 32 and 33 restores relay 3% and magnet 26 to normal. Upon thenext change of polarity if the corrected distributer is still inadvance, the shifting of the armature 5 from the contact l to contact 3will remove potential of battery 6 from the primary of transformer 35,induce an impulse in the secondary, and as the last set of contacts 15and 16 will be connected through brushes 17 and 4:6 in the case assumed,will cause the energization of relay 34 and magnet 26 as before to setback the distributer brushes.

Thus for every change of polarity a synchronizing impulse will be sentthrough the transformer and it the distributers are not in exactsynchronism the brushes of the corrected distributer will be retarded orset back.

I claim,

1. A synchronizing system comprising a transmission. line, a rotatablebody associated with said line and providing current impulses therefor,a second rotatable body also associated with said line, an independentsource of power for driving said second body, a line relay responding tothe changes of current polarity over said line, a transformer respondingto the actuation of said relay to provide local correcting currentimpulses, and means controlled thereby for varying the speed of saidsecond body.

2. A synchronizing system comprising a second mentioned body to controlthe speed thereof.

In Witness Whereoi I hereunto subscribe my name this 31st day of March,A. D. 1914.

AMOS F. DIXON. Vfitnesses F. T. Woonwann, E. N. Anairs.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

